Use of immobilized enzymes in an expanded or fluidized bed has certain advantages over use of immobilized enzymes in a fixed bed. Reference is made to U.S. Pat. Nos. 3,928,143 and 4,138,290 for detailed discussion of how fluidized and expanded beds may be employed to carry out enzyme catalyzed reactions. The most important advantages of operating in an expanded or fluidized bed over the operating performance in a fixed bed is that plugging is totally avoided in an expanded or fluidized bed and that it is possible to use substrates with particulate materials therein in an expanded or fluidized bed.
In spite of these advantages, almost all industrially enzyme catalyzed continuous processes in which immobilized enzymes are used, to the date hereof, are performed in fixed bed, inter alia because in an expanded or fluidized bed the particles with the enzymatic activity are worn down during operation as a result of collisions between the individual particles.
Thus, a need exists for immobilized enzyme-containing particles suitable for use in an expanded or fluidized bed which have a better abrasion resistance than the previously known immobilized enzyme-containing particles that were purported to be suitable for use in an expanded or fluidized bed.